This application requests a Zeiss 510/META laser scanning confocal microscope with environmental chamber to replace our 11 year old Zeiss 410 microscope, which is part of the Imaging Core (Core Director, O. Kovbasnjuk, Ph.D., who is PI of this application) of an NIH NIDDK Core Development Center (R24, DK064388, "Hopkins Basic Science Digestive Diseases Core Center", PI, M. Donowitz, M.D.). The Zeiss 510/META microscope will allow us to provide state-of-the-art fluorescence imaging capabilities for 5 major interacting investigators, who are supported by the NIH NIDDK Core Development Center and who are closely interacting. There are also 6 minor users supported by the same Core Center who have their laboratories in the Ross Research Building, which houses the GI Core Center and the Zeiss confocal. In addition to being part of an NIH funded Core Center, the 510/META will be a resource for other JHUSOM scientists needing an environmental chamber on a confocal and will be available on a fee-for-service basis to scientists in a major Hopkins research facility (Ross Building). The 410 no longer satisfies our users' needs which can be met by the 510/META. This is due to 1) Deterioration of the Zeiss 410 PMT's and pin holes plus its outmoded software and tenuous computer support so the entire system will not be functional once the current computer fails. 2) Lack of spectral scanning capability needed for FRET applications. 3) Need for extensive use of FRET and FRAP with improved precision on 510 due to more precise pixel alignment than 410. The features of the Zeiss 510/META which are necessary to accomplish the diverse biomedical projects and which do not exist on the Zeiss 410 model to be replaced include: multitracking technology for speed and precise pixel localization; Zeiss LSM510 and Axiovision software for rapid signal processing and analysis; and a live cell chamber with temperature and CO2 controls needed for prolonged live cell imaging. The JHUSOM Imaging Core is not able to provide adequate time for the physiologic studies proposed in the R24 Center. This is preventing the proposed FRET studies and overnight constant temperature chamber studies. Importantly, no instruments available on a fee-for-service basis at JHUSOM are equipped with a live cell chamber. The Zeiss 510/META will be installed in the NIH NIDDK Core Center Imaging Core Facility, a location that is central to most of the users. It is anticipated that 75% of the 40 hr week will be used by the 5 major plus 6 minor users, with the remaining 25%, representing ~10-15 additional hrs/week, will be taken up by fee-for-service users, mostly from the Ross Building plus other Hopkins users needing the live cell chamber. [unreadable] [unreadable] [unreadable]